If the rising generation of young progressives allow themselves to believe Donald Trump is just a bump in the road to inevitable Democratic success. . . they are in for even more rude awakenings in the future.

For being the largest generation in American history, the Millennial generation inspires a ridiculous degree of overgeneralization. It is possible for a generation of this size to include more entrepreneurs and more slackers, more libertarians and more socialists, more dedicated believers and more unchurched nones. It is also a generation split in two given the very different experiences within the cohort as it relates to social media. If you were born in the first half of the 1980s, you came to cell phones and social media in college and professionally; if you were born in 1990 or beyond, you have no memory of a world without cell phones and social media. These have very different lessons in how you view the world, and in your susceptibility to viewing it entirely through the warped lens social media experiences can create.

This has an impact on our politics as well. If you were born in 1980, you could cast a vote starting in 1998, and you experienced multiple elections without the existence of YouTube and Twitter. If you were born in 1990, around the peak of the birthrate for the generation, the first time you could cast a vote was in 2008, in the first election truly influenced by social media. The lessons you learned from that election were charted by an inspirational young political figure, whose status as a relative novice didn’t prevent you from trusting that he could bring incredible change to the existing political system.

But in retrospect, the Obama years were not a good time for positive growth or introspection on the part of Millennials. This is in part due to the near-constant hype of demographic destiny on the part of the Democratic intelligentsia. The “emerging Democratic majority” charted by John Judis and Ruy Teixeira in 2002 has been the underpinning for an enormous amount of hubris on the part of party leaders, confident that a new multicultural coalition would place them in power forever, and that the only thing holding them back is a handful of racist white male Fox News viewers. Victory, in the framing of many Democrats, was just a matter of time, waiting for old Republicans to die off and ushering a new progressive era.

Thanks to social media, Millennials allowed themselves to feel comfortable in information silos which served to vindicate their opinions about the world and this moralistic “arc of history” frame. It was not welcome to question such assumptions. The most important thing became virtue signaling – ensuring that you were not making any public errors on social media that would indicate you had taken up with the wrong team, shown any openness to cultural appropriation, or displayed any tendency to offer aid and comfort to those on the wrong side of history.

Online it means we can be blindsided by the opinions of our friends or, more broadly, America. Over time, this morphs into a subconscious belief that we and our friends are the sane ones and that there’s a crazy ‘Other Side’ that must be laughed at — an Other Side that just doesn’t ‘get it,’ and is clearly not as intelligent as ‘us.’ But this holier-than-thou social media behavior is counterproductive, it’s self-aggrandizement at the cost of actual nuanced discourse and if we want to consider online discourse productive, we need to move past this.

What is emerging is the worst kind of echo chamber, one where those inside are increasingly convinced that everyone shares their world view, that their ranks are growing when they aren’t. It’s like clockwork: an event happens and then your social media circle is shocked when a non-social media peer group public reacts to news in an unexpected way. They then mock the Other Side for being ‘out of touch’ or ‘dumb.’

Millennial progressives didn’t just believe their own hype and the hype of others around them about the demographic destiny which would inevitably result in progressive success. They allowed this hype to create a blinkered view of the country, a view which stopped them from even having the ability to understand a reason why anyone would vote for Donald Trump.

In Jonathan Martin’s piece on the economic messages of the Democratic Party today, there is an astonishing admission from Randi Weingarten about the negative effects of coastal elites on the party’s message.

Randi Weingarten, the president of the American Federation of Teachers, said the growing importance of social issues in the national debate and Democrats’ reliance on wealthy donors on the two coasts who are more focused on cultural liberalism than on economic solidarity had, together, left the party somewhat disconnected from the working class. ‘Social issues now have become central, rather than class issues,’ said Ms. Weingarten, who recommended what she called a ‘both/and’ approach.

But there is less interest from Democrats like Jason Kander, a Millennial, who rejected the idea that a return to Clintonian triangulation is needed.

Jason Kander, a Missouri Democrat who lost to Senator Roy Blunt by just three percentage points while Mrs. Clinton lost the state by 19, dismissed what he called ‘the old construct about Blue Dogs,’ referring to the moderate-to-conservative Democratic group that was once robust in the South and in border states. ‘I ran on a progressive message: economic fairness, college affordability and equality for the L.G.B.T. community,’ Mr. Kander said. ‘We should not hide from our beliefs or apologize. We should lean in, full force.’

Democratic Millennials like Kander have been raised to believe that this message is the future. No wonder they would display less self-reflection after a loss. No wonder the younger cohort in particular is reduced to tears, skipping classes and going to counseling. The very idea that the progressive message is incomplete, that there is something about it which doesn’t appeal to a portion of the coalition key to Democratic success in the 1990s, doesn’t compute for them. Everyone around them – the media they consume, their friends online, the cultural influencers they look to – informs an opinion of moral rightness and political inevitability. Everyone they listened to told them they were right. How could so many be wrong?

If the rising generation of young progressives allow themselves to believe Donald Trump is just a bump in the road to inevitable Democratic success, that nothing needs to change in their message or their agenda, it could be that they are in for even more rude awakenings in the future. The sooner they wake up to this political reality – that the Obama coalition is harder to reassemble than just checking the right boxes and rolling out the right celebrity endorsements, and that the moment requires introspection and reevaluation of their prior assumptions – the sooner they will grow to understand the nation as it is, not as they imagined it to be.